pesticide residues in selected vegetables in several

Annals of Sri Lanka Department of Agriculture 2017. 19 (2): 188 - 208

PESTICIDE RESIDUES IN SELECTED VEGETABLES IN SEVERAL

GROWING AREAS BY GC/MS USING QuEChERS TECHNIQUE

P.W.Y. LAKSHANI1, M.K.L.K.RAJAPAKSHA1 and K.SENDTHURAN2

1 Registrar of Pesticide Office, No.1056, Kandy Road, Gatembe, Sri Lanka 2 Department of Food Science and Technology, Wayamba University of Sri Lanka

ABSTRACT

Growing concerns over food safety and the expanding world agricultural

trade have led to the enforcement of strict pesticide regulations including in Sri Lanka.

Thus, this study was undertaken to evaluate the Maximum Residue Levels (MRL) of

selected vegetables in the open market in three locations. For the evaluation of pesticide

residues, a total of 90 samples of vegetables including tomato (Solannum lycopersicum),

capsicum (Capsicum annuum) and cabbage (Brassica olerecea) were collected during the

period of 2016 March to 2016 November from different vegetable markets in Nuwara

Eliya, Puttlam and Matale districts. Samples were extracted according to the

QuEChERS, AOAC code 2007.01 by application of a single step buffered acetonitrile

extraction and salting out liquid-liquid partitioning from the water in the sample with

MgSO4 and clean-up is done by dispersive solid phase extraction. Concentrated samples

were analyzed by GC/MS in Selective Ion Mode (SIM) and presence of pesticides was

confirmed with Retention Time (RT) and Mass Spectrum (MS). Matching of RT and MS

data of the sample peak with that of the CRM gave unambiguous identification of the

pesticides present in the sample. Recovery studies at three spiking concentration levels,

namely, 1 LOQ, 5 LOQ and 10 LOQ varied from 80.7 to 99.1 % with Relative Standard

Deviation (RSD) below 20%. Out of 90 samples tested, 30 samples were contaminated

with pesticide residues. The results of this study provide important information about

contamination of pesticide residues in tomato, capsicum and cabbage available at

markets of Nuwara Eliya, Puttlam and Matale districts and recommend that monitoring

studies should be expanded to other districts in order to come out with a strong national

policy on safer use of pesticides in vegetable cultivation in Sri Lanka.

Key words: LOQ, Pesticide residues, QuEChERS,

PESTICIDE RESIDUES IN SELECTED VEGETABLES. 189

INTRODUCTION

Pesticides are extensively used in agricultural production to control

pests, diseases, weeds and other plant pathogens in an effort to reduce or

eliminate yield losses and extend the storage life food commodities. However,

indiscriminate use of pesticides which has become a common practice of

present day agriculture leads to the accumulation of pesticide residues in

agricultural produce, and causes numerous health and environmental impacts.

The prescribed pre-harvest intervals in pesticide applications are neglected by

majority of vegetable farmers due to high demand of fresh vegetables (Latif et

al., 2011). Pesticides contamination is a worldwide public health concern and

also a one of the crucial issue in international. Several pesticides can persist in

the environment for a long time. Therefore, in the context of health, it is

necessary to control or minimize the application of pesticides on crops.

Agriculture is the cornerstone of Sri Lanka’s economy which accounts

for 1.7 million farm families in a population of about 22 million. Agriculture

sector contribute 11 % to Gross Domestic Product in Sri Lanka. Arable land,

percentage of total land area is 19.1 and permanent cropped land, percentage

of agricultural land area is 37.4. (Central Bank Report, 2014).

Sri Lanka produces around 710,000 metric tons of vegetables and

around 540,000 metric tons of fruits annually (Esham et al. 2006). In Sri

Lanka, many types of vegetables are grown in various regions. Up country

region is ideal for temperate crops such as carrot, leeks, cabbage, chinese

cabbage, cauliflower, salad leaves, beet, bean, bell pepper, salad cucumber,

tomatoes, cherry tomatoes and strawberries while the Low Country areas are

suitable for a variety of tropical fruits and vegetables ranging from green

chilli, red onion, pumpkin, cucurbits, bitter gourd, melon, sweet and sour

banana types, Cavendish banana, queen pineapple, papaya, mango, lemon and

gherkins etc. (Hanif et al,2006)

Sri Lanka is ranked 4th amongst Asian countries on pesticide use

(1,695 tons of active substances). There are approximately 114 active

substances and nearly 440 agricultural pesticides in commercial use. The data

190 Lakshani et al.

available in year 2014 indicate that an abrupt decline in pesticide imports by

about 30% than the previous year (2013) due to stringent control over high

volume pesticides such as chlorpyrifos, carbaryl, carbofuran and propanil.

Further reduction is imminent due to banning of glyphosate, which accounts

for approximately 25% reduction (of weedicide formulations) and/or 18%

reduction (of all pesticides formulations) of imports in to the country

(Department of Agriculture, 2015). Imported quantities of pesticides during

year 2012-2015 are presented in Table 1.

Given the potential risk of pesticides for public health, the use of

pesticides in fruit and vegetable production is subjected to constant

monitoring. Pesticide residues are specified substances in food, Agricultural

commodities or animal feed resulting from the use of a pesticide.

Table 1. Imported pesticide quantities during the period of 2012-2015

2012 2013 2014 2015

Volume Volume Volume Volume

(mt) (mt) (mt) (mt)

Formulation

Insecticide 959.37 1243.46 702.91 1759.06

Herbicide 4753.01 5958.32 4081.83 2862.74

Fungicide 776.44 981.15 935.92 1233.8

Monitoring of pesticide residues in food stuffs have been carried out

for decades in most developed countries even though such initiatives are not in

the routine agenda of relevant agencies of Sri Lanka. Therefore, the objective

of present study was to assess the concentration of pesticide residues in fruits

and vegetables from markets in Nuwara Eliya, Puttlam and Matale districts


Table 2. Details of pesticide selected for the study *

Pesticide CAS No Chemical type Main

use

ADI

mg/kg

b.w

Hazard

class AI

A I LD50

rat oral

mg/kg

Cadusafos 95465-99-9 Organophosphate I 0.0005 1b 37

Deltamethrin 52918-63-5 Pyrethroid I 0.01 11 135

Diazinon 333-41-5 Organophosphate I,A 0.005 11 300

Chlorpyrifos 2921-88-2 Organophosphate I 0.01 11 135

Phenthoate 120068-37-3 Organophosphate I 0.001 11 400

Prothiofos 34643-46-4 Organophosphate I 0.005 11 925

Oxyfluorfen 42874-03-3 Diphenyl ether H 0.01 IV >5000

Tebuconazole 107534-98-3 Triazole F 0.03 11 1700

Note: *WHO recommended classification of pesticides by hazards and guideline to

classification 2009. International programme on chemical safety

Table 3. Different Maximum Residue Levels

Cordex MRL Global MRL EU MRL

Tom Capsi Cabb Tom Capsi Cabb Tom Capsi Cabb

Cadusafos - - - - - - 0.01 -* 0.01

Deltamethrin 0.3 - - 0.2 - - 0.3 -* 0.5

Diazinon 0.5 - 0.5 - - - 0.01 -* 0.05

Chlorpyrifos - - 1 - - 1 0.01 -* 0.01

Phentoate - - - - - - -* -* -*

Prothiofos - - - - - - -* --* -*

Oxyfluorfen - - - - - 0.05 0.05 -* 0.05

Tebuconazole 0.7 - 1.0 1.3 - - 0.9 -* -*

Note: *A general default MRL of 0.01 mg/kg applies where a pesticide is not specifically

mentioned; -Not available; Tom=Tomato; Capsi=Capsicum; Cabb=Cabbage

MATERIALS AND METHODS

Selection of Pesticide

At present, Organochlorine pesticides are not used due to their

bioaccumulation ability. The pesticide categories currently registered in Sri

Lanka belongs to hazard classes II, III, and IV of the WHO hazard

classification. Cadusafos, Deltamethrin, Diazinon, Chlorpyrifos, Phenthoate,

Prothiofos, Oxyfluorfen and Tebuconazole have been selected for the study

192 Lakshani et al.

due to their extensive usage, toxicological effects and available analytical

facilities. Cadusafos is currently registered under the restricted category and

Chlorpyrifos is already banned since 2013. These two were selected for the

study due to presence of counterfeits in the markets in selected districts

Certified Reference Materials (CRM)

Certified reference materials were obtained from Sigma Aldrich for all

the pesticide used in the study. Percent purity of each CRM is given in Table

4.

Table 4. Present purity of chemical standards.

Pesticide Purity %

Diazinon 98.5

Chlorpyrifos 99.7

Oxyfluorfen 98.7

Tebuconazole 99.3

Cadusafos 99.5

Prothiofos 99.8

Deltamethrin 99.4

Phenthoate 99.4

Instrument Details and Operating parameters

Concentrated samples were analyzed by GC/MS in selective ion

mode. Presence of pesticides was confirmed with Retention time (RT) and

Mass spectrum (MS). Matching of RT and MS data of the sample peak with

that of the CRM gave unambiguous identification of the pesticides presented

in the sample (Lehotay et al., 2007). Agilent 6890/5975B GC-MSD (Mass

selective Detector) equipped with DB 35 MS fused silica capillary column

(Agilent J & W GC column, 5% phenylated methyl siloxane, 30 m length,

0.25 mm internal diameter and 0.25 μm film thickness was used for analysis

of pesticide. Analysis was carried out using temperature programming of

initial temperature 80 °C for 1 min followed by a ramp rate of 10°C min-1up to

a temperature of 160 °C with a hold time of 1 min followed by 6°C min ramp

to a temperature of 250 °C with a hold time of 1 min, followed by 10°C min

ramp to a temperature of 300 °C with a hold time of 5 min. The injector was

operated in splitless mode at 280 oC temperature. The interface, ion source and


quadrapole temperatures were set at 280 oC and 250oC and 150 oC

respectively. The instrument was operated at electron impact mode (EI) with

electron energy 400 ev. Helium was used as carrier gas at a flow rate of 1

ml/min. Solvent delay time was given as 6.5 min. (Lehotay et al., 2005).

Preparation of standard stock solution (Strength approximately 500

mg/L)

The stock solution of 500 mg/L was prepared by certified Reference

Materials (CRM) of pesticide having specific purity with traceability.

Standards were taken out from freezer (–18 to-20 oC) and kept them till room

temperature was reached. 500 mg/L standard stock solutions were prepared by

HPLC grade acetone and kept in the refrigerator at 4 - 6 oC.

Intermediate stock solution (Strength approximately 50 mg/L)

Stock solution of 500 mg/L was taken out from the refrigerator and

leave to reach room temperature. Intermediate solutions of 50 mg/L were

prepared by diluting the stock solution and stored in the refrigerator at 4 - 6 o

C.

Primary working Standards Solution (Strength approximately 5 mg/L)

Intermediate stock solutions were taken out from refrigerator and leave

to reach the room temperature. 5 mg/L primary working standard contain all

pesticides was prepared by HPLC grade acetone and store in the refrigerator at

4 - 6 o C.

Preparation of working standards

Primary working standard solutions was taken out (Approximately 5

mg/L) storage bottle from refrigerator and leave it to reach the room

temperature. If moisture observed on the storage bottle surface, gently wipe

out using a tissue paper. Working standards of 0.2, 0.5, 1.0, 1.5, 2 .0 mg/L was

prepared from the Primary working standard.

194 Lakshani et al.

External standards calibration procedure

Calibration standards were prepared at five concentration levels for

each pesticide. The analysed concentration should be within the lowest and

highest calibration standards linearity is accepted only if the correlation factor

is more than 0.990.

Steps in pesticide residue analysis

Pesticides may occur in food at very low concentrations, usually at

ppm levels. A variety of analytical methods are currently used to detect

pesticide residues and all contained certain basic steps that include sampling,

sample preparation, extraction, clean up and identification (Lesueur et al.,

2008)

Table 5. Selected pesticides, retention time and their target ions

Compound Name Retention Time/min Target Ion M/Z

Cadusafos 13.983 253,231,233

Deltamethrin 15.275 159,158,127

Diazinon 15.948 304,179,199

Chloropyrifos 19.566 314,197,199

Phenthoate 20.342 274,246,164

Prothiofos 22.308 309,267,162

Oxyfluorfen 22.824 252,302,331

Tebuconazole 26.201 250,125,126

Figure 1. Chromatograms for Standard in GC/MS.


Sample preparation procedure

Tomato, capsicum and cabbage samples collected at local markets

from Nuwara Eliya, Puttalam and Dambulla were stored in a refrigerator and

taken out to set to room temperature. Samples were cut coarsely with a knife

and grinded separately by using a blender. The blender was clean thoroughly

before being used for the next sample to avoid cross contamination. A sample

of 10 g ± 0.1 g was transferred in to 50 ml Teflon tube and 6 g of anhydrous

magnesium sulphate, 1.5 g of anhydrous sodium acetate or 1.5 g of sodium

chloride were added. 10 ml of 1 % acetic acid in acetonitrile was added in to

the sample tube and vortex for 1 minute and centrifuge 3000 rpm for 3

minutes (Nguyen et al., 2008). Aliquot from supernant layer was transferred in

to the dispersive 15 ml SPE tube containing 400 mg PSA, 1200 mg

magnesium sulphate. In the presence of water magnesium sulphate tends to

form lumps, which can harden rapidly. This can be avoided if immediately

after the addition of the salt mixture the centrifuge tube is shaken vigorously

for a few seconds. SPE (Solid Phase Extraction) tubes were Vortex for 1

minute and centrifuge 3 minutes at 3000 rpm. Finally supernant layer was

transferred in to rotary evaporator. Content was evaporated using a rotary

evaporator at a temperature below 40o C concentrate the solvent near to dry

and add 1 ml of acetone to dissolve. The solution was passing through 0.45

micro meter HDPE filter by using the plastic syringe and transfers the extract

to GC vial. Finally extract is subject to GC/MS for quantitative analysis

(AOAC, 2007).

Calculation

As the external standard calibration procedure was used, calculate the

amount of material injected from the peak response using the calibration curve

(Figure 1).

Linearity

All calibration curves were prepared and correlation coefficient (r)

values were calculated with each calibration curve. Each calibration curve was

prepared with multi-pesticide standard solutions, including the blank standard

solution. The analytical calibration should extend over a range appropriate to

the lowest and highest nominal concentration of the analysed in relevant

196 Lakshani et al.

analytical solutions at least ±20%. At trial linearity the linearity criteria of

r2 ≥ 0.98-0.99 have to be achieved (Yawar, et al., 2011)

Determination of recovery

Replicates of high spiked sample and low spiked sample were analyzed

using candidate method and recovery was estimated. Mean recoveries for each

level should be in the range 70-110%, with acceptability RSD ≤ 20%

(Nguyen, et al., 2008). Mean recovery percentages for each pesticide are

present in figure 3.

Figure 2. Calibration curve for selected pesticides

Table 6. Correlation coefficient for selected Pesticides

Chemicals R2

Cadusafos 0.999

Deltamethrin 0.998

Diazinon 0.999

Chlorpyrifos 0.999

Phenthoate 0.998

Prothiofos 0.994

Oxyfluorfen 0.997

Tebuconazole 0.999

Acceptable Daily Intake (ADI)

ADI of a chemical is the daily intake, which during an entire lifetime,

appears to have no appreciable risk to the health of the consumer on the basis

of all the known facts at the time of the evaluation of the chemical. It is


Tebuca

nazol

e

Proth

iopho

s

Phenth

oate

Oxy

fluro

fen

Diazinon

Delta

met

hrin

Chloph

yrip

hos

Cadus

aphos

1 00

80

60

40

20

0

Pesticide

Pest

icid

e R

eco

very

%

Chart of Pesticide Recovery Precentage

expressed in mg/kg of body weight. ADIs are derived from the results of long

term feeding studies with laboratory animals.

No Observed Adverse Effect Level (NOAEL)

It is the highest dose of substances that does not cause any detectable

toxic effects in experimental animal studied. It is expressed in mg/kg body

weight per day.

Figure 3. Mean Recovery value for selected pesticides

Maximum Residue Level (MRL)

MRL is the maximum concentration of a pesticide residues (mg/kg) to

be legally permitted in or on food commodities and animal feeds

recommended by the CORDEX or National Regulatory Authority. During the

Study, CORDEX MRL data are compared with the global MRL data and EU

MRL data as shown in table 3. According to that EU has most stringent data

base and default is set to 0.01 mg/kg and it covers most of the crop and

pesticide. Therefore, EU MRL data was used to compare the detectable

residue level (CODEX alimentarius, 2015).

198 Lakshani et al.

Limit of Detection (LOD)

LOD for pesticide residue analysis in vegetable and fruit was 40 ppb.

LOD value for the Matrix converted for pesticide residue was presented on

table 6. (EU MRL, 2015)

Table 6. Matrix converted LOD Values for selected pesticides

Pesticide LOD with uncertainty mg/kg

Cadusafos 0.040±0.0061

Deltamethrin 0.040±0.0064

Diazinon 0.040±0.0061

Chlopyrifos 0.040±0.0067

Phenthoate 0.040±0.0068

Prothiofos 0.040±0.0063

Oxyfluorfen 0.040±0.0062

Tebuconazole 0.040±0.0064

RESULTS AND DISCUSSION

Out of 90 samples analyzed, no samples were found to be

contaminated with Cadusafos or Deltamethrin. EU has the most stringent

MRL data and EU MRL was used to compare the detectable residue level.

Each 30 samples of tomatoes, capsicum and cabbage from Nuwara Eliya,

Puttalam and Matale districts were collected for the study. Out of 90 samples

analysed, 30 were found to be contaminated with the residues of different

pesticides. It was determined that 4 samples were found to be contaminated

with Diazinon with exceeding EU MRLs. Summary of the results of GC/MS

analysis of samples are given in figure 4 and table 8. The highest amount of

Diazinon found in cabbage was 0.170 mg/kg, collected from Dambulla.


Table 8. Sample analysis data for Diazinon

Area Matrix Total Sample No

No of Contami-nated

No of Sample above EU MRL

Mean mg /Kg

Range mg /Kg

Nuwara Eliya Tomato 10 - - - -

Capsicum 10 01 01 0.042 0.042

Cabbage 10 - - - -

Puttalam Tomato 10 - - - -

Capsicum 10 02 02 0.089 0.048-0.130

Cabbage 10 - - - -

Dambulla Tomato 10 - - - -

Capsicum 10 - - - -

Cabbage 10 01 01 0.170 0.170

Figure 4. Chart of mean Diazinon level detected in vegetables available at Selected Areas

Of the 90 samples, including 30 samples of tomatoes, 30 samples of

capsicum and 30 samples of cabbage, only 7 samples were contaminated with

Chlorpyrifos and these 7 samples had residue content more than EU MRL

value. Chlorpyrifos contamination was only presented with Nuwara Eliya and

Puttalam districts and out of these 7 samples almost 6 samples were found in

market located in Puttalam district. Chlorpyrifos has been already banded on

2013 and the contamination may be due to counterfeits of Chlorpyrifos. The

highest amount of Chlorpyrifos found in cabbage was 0.130 mg/kg, collected

from Puttalam District. Summary of the results of GC/MS analysis of samples

are given in Figure 5 and Table 9.

200 Lakshani et al.

Table 9. Sample analysis data for Chlorpyrifos

Area Matrix Total

Sample

No

No of

Contaminated

No of

Sample

above

EU

MRL

Mean

(mg /Kg)

Range

(mg /Kg)

Nuwara Eliya Tomato 10 01 01 0.061 0.061

Capsicum 10 - - - -

Cabbage 10 - - - -

Puttalam Tomato 10 02 02 0.096 0.062-0.130

Capsicum 10 02 02 0.130 0.130

Cabbage 10 02 02 0.130 0.130


Capsicum 10 - - - -

Cabbage 10 - - - -

Figure 5. Chart of mean Chlorpyrifos level detected in vegetables available at Selected

Areas.

According to the analysis data present in Figure 6 and Table 10, only

04 samples were contaminated with Phenthoate and these 4 samples had

residue content more than EU MRL value. The highest amount of Phenthoate

found in vegetables collected from Puttalam and Nuwara Eliya districts and

the value was 0.200 mg/kg. Summary of the results of GC/MS analysis of

samples are given in Figure 6 and Table 10.


Table 10. Sample analysis data for Phenthoate.

Area Matrix Total

Sample

No

No of

Contaminated

No of

Sample

above

EU

MRL

Mean

(mg

/Kg)

Range

(mg

/Kg)

Nuwara Eliya Tomato 10 - - -

Capsicum 10 01 01 0.200 0.200

Cabbage 10 - - - -


Capsicum 10 01 01 0.180 0.180

Cabbage 10 01 01 0.200 0.200


Capsicum 10 01 01 0.180 0.180

Cabbage 10 - - - -

Figure 6. Chart of mean Phenthoate level detected in vegetables available at Selected

Areas.

According to the analysis data present in Figure 7 and Table 11, of the

90 samples tested, The highest amount of prothiofos found in vegetables

collected from Puttalam and Nuwara Eliya districts and the value was 0.200

mg/kg Summary of the results of GC/MS analysis of samples are given in

Figure 7 and Table 11.

202 Lakshani et al.

Table 11. Sample analysis data for Prothiofos

Figure 7. Chart of mean Prothiofos level detected in vegetables available at Selected

Areas.

Of the 90 samples tested, only 4 samples were contaminated with

Oxyfluorfen and these 4 samples had residue content more than EU MRL

value. The highest amount of Oxyfluorfen found in tomato was 0.490 mg/kg,

collected from Matale District. Summary of the results of GC/MS analysis of

samples are given in Figure 8 and Table 12.

Area Matrix Total

Sample

No

No of

Contami-

nated

No of

Sample

above EU

MRL

Mean

(mg

/Kg)

Range

(mg /Kg)


Capsicum 10 - - - -

Cabbage 10 - - - -


Capsicum 10 - - - -

Cabbage 10 01 01 0.170 0.170

Dambulla Tomato 10 02 02 0.146 0.052-0.240

Capsicum 10 - - - -

Cabbage 10 - - - -

Prothiofos

Level mg/kg


Table 12. Sample analysis data for Oxyfluorfen

Area Matrix Total

Sample

No

No of

Contami-

nated

No of

Sample

above EU

MRL

Mean

(mg

/Kg)

Range

(mg /Kg)


Capcicum 10 02 02 0.139 0.078-0.200

Cabbage 10 - - - -

Puttalam Tomato 10 01 01 0.200 0.200

Capcicum 10 - - - -

Cabbage 10 - - - -

Dambulla Tomato 10 01 01 0.490 0.490

Capcicum 10 - - - -

Cabbage 10 - - - -

Figure 8. Chart of mean Oxyfluorfen level detected in vegetables available at Selected

Areas

Out of 90 samples only 13 samples were contaminated with

Tebuconazole and from these 13 samples, only 9 samples had residue content

more than EU MRL value. The highest amount of Tebuconazole found in

vegetable was 0.370 mg/kg, collected from Dambulla. Summary of the results

of GC/MS analysis of samples are given in Figure 9 and Table 13.

204 Lakshani et al.

Table 13. Sample analysis data for Tebuconazole.

Area Matrix Total

Sample

No

No of

Contami

nated

No of

Sample

above EU

MRL

Mean

(mg

/Kg)

Range

(mg /Kg)

Nuwara Eliya Tomato 10 03 - 0.093 0.061-0.150

Capsicum 10 03 03 0.090 0.060-0.150

Cabbage 10 02 02 0.060 0.060


Capsicum 10 01 01 0.150 0.150

Cabbage 10 01 01 0.058 0.058

Dambulla Tomato 10 01 - 0.370 0.370

Capsicum 10 - - - -

Cabbage 10 02 02 0.138 0.084-0.330

Figure 9. Chart of mean Tebuconazole level detected in vegetables available at Selected

Areas.

The mean concentrations and range of pesticide residues found in

tomato, capsicum and cabbage available at Nuwara Eliya, Puttalam and

Dambulla local markets are summarized in table 14.


Area

Dam

bulla

Puttala

m

Nuwara

eliy

a

Tebuca

nazole

Oxy

fluro

fen

Prot

hiophos

Phenth

oate

Chlophy

riphos

Diazin

on

Deltam

ethrin

Cadusa

phos

Tebu

canazo

le

Oxy

fluro

fen

Proth

iopho

s

Phenth

oate

Chloph

yrip

hos

Diazin

on

Delta

meth

rin

Cadusa

phos

Tebuca

nazol

e

Oxyf

luro

fen

Proth

ioph

os

Phenthoat

e

Chlop

hyrip

hos

Diazin

on

Delta

met

hrin

Cadusa

phos

0.30

0.25

0.20

0.1 5

0.1 0

0.05

0.00

Det

ecte

d R

esid

ue

Leve

l mg

/Kg

Detected Pesticide Residues in Different Areas

Table 14. Mean concentration of pesticide detected.

Overall the data revealed that, the high presence of pesticide residues

was appeared in Puttalam . Capsicum and cabbage available at Puttalam

market have high frequency of contamination with pesticide residues. The

highest level of contamination was found to be 0.490 mg/kg of Oxyfluorfen on

tomato presence in Dambulla Economic Centre. The result of the study

indicates that Tebuconazole has higher possibility for contamination in all

Districts. Mean level of detected pesticide in Nuwara Eliya, Puttalam and

Matale Districts were presented by the Figure 10.

Figure 10. Detected Pesticide Residues in Selected Areas

Area Matrix Mean Pesticide Residue detected (mg/Kg)

Cad

usa

fos

Del

tam

eth

rin

Dia

zin

on

Ch

lorp

yrif

os

Ph

enth

oate

Pro

thio

fos

Oxy

flu

orfe

n

Teb

uco

naz

ole

Nuwara Eliya Tomato - - - 0.061 - - - 0.093

Capsicum - - 0.042 - 0.200 - 0.139 0.090

Cabbage - - - - - - - 0.060

Puttalam Tomato - - - 0.096 - - -

Capsicum 0.089 0.130 0.180 - - 0.150

Cabbage 0.130 0.200 0.170 - 0.058

Dambulla Tomato - - - - - 0.146 0.490 0.370

Capsicum - - - - 0.180 - - -

Cabbage - - 0.170 - - - - 0.138

206 Lakshani et al.

CONCLUSION

Diazinon, Chlorpyrifos, Phenthoate, Prothiofos, Oxyfluorfen and

Tebuconazole were found in tomato, capsicum and cabbage samples and

Deltamethrin and Cadusafos were not detected on analysed vegetable samples.

According to the analysed data 33 % of samples were contaminated with

pesticide residues. Also already banded pesticide Chlorpyrifos was used as a

counterfeit in Nuwara Eliya and Puttalam districts.

Capsicum and cabbage available at Puttalam market have high

frequency of contamination with pesticide residues. The highest level of

contamination was found to be 0.490 mg/kg of Oxyfluorfen on tomato

presence in Dambulla Economic Centre. The result of the study indicates that

Tebuconazole has higher possibility for contamination in all Districts.

The above results suggest that the consumers of the Nuwara Eliya,

Puttalam and Matale districts were exposed to concentration of pesticides that

may cause chronic diseases. On the basis of the above findings the results

recommended the need for continuous surveillance and monitoring

programmes for pesticide residues in other 22 districts in order to protect the

end user for the indiscriminate exposure of pesticides.

REFERENCES

Association of Official Analytical Chemists International. 2011. AOAC Official Method

2007- 01 Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning

with Magnesium Sulfate. Official Methods of Analysis of AOAC International. 90

(2): 17 – 26.

Central Bank of Sri Lanka, 2014. Annual Report 2014.

Department of Agriculture. 2015. Pesticide Statistics of the Office of the Registrar for the

Pesticides Industry, Office of the Registrar of Pesticides, Department of Agriculture,

Peradeniya, Sri Lanka.


European Commission, Maximum Residue Limit. 2015. http://www. ec.europa.eu (Accessed

on15. 7. 2016).

Esham, M. 2006. Procurement Behavior of the Fruit and Vegetable Industry in Sri Lanka.

Journal of Rural Problems. pp 36–44.

Food and Agriculture Organization. 2005. International Code of Conduct on the Distribution

and Use of Pesticides. http://www.fao.org/docrep/008/af340e/af340e0k.htm#bm20

(Accessed on 12. 07.2016).

CODEX alimentarius. http://www.fao.org/cordexalimentarius (Accessed on 15. 07. 2016).

Food and Agriculture Organization Statistics (FAOSTAT). 2015. Food and Agriculture

Organization of the United Nations Statistics Division.

http://faostat3.fao.org/download/Q/QC/E (Accessed on 10.07. 2016).

Hanif, R., Z. Iqbal and M. Iqbal. 2006. Use of vegetables as nutritional food: role in human

health. Journal of Agricultural and Biological Science. 1(1): 18–22.

Koesukwiwat, U., S.J. Lehotay, S. Miao and N. Leepipatpiboon. 2010. High throughput

analysis of 150 pesticides in fruits and vegetables using QuEChERS and low-

pressure gas chromatography-time-of-flight mass spectrometry. Journal of

Chromatography A. 1217 (43): 6692–6703.

Lehotay, S.J., A. de Kok, M. Hiemstra and P. V. Bodegraven. 2007. Determination of

pesticide residues in foods by acetonitrile extraction and partitioning with magnesium

sulfate: Collaborative study. Journal of AOAC International. 90 (2): 485–520.

Lehotay, S.J., A. de Kok, M. Hiemstra and P. V. Bodegraven. 2005. Validation of a fast and

easy method for the determination of residues from 229 pesticides in fruits and

vegetables using gas and liquid chromatography and mass spectrometric detection.

Journal of AOAC International. 88(2): 595–614.

Lesueur, C., P. Knittl, M. Gartner, A. Mentler and M. Fuerhacker. 2008. Analysis of 140

pesticides from conventional farming foodstuff samples after extraction with the

modified QuECheRS method. Food Control. 19(9): 906–914.

Nguyen, T.D., J.E. Yu, D.M. Lee and G.H. Lee. 2008. A multiresidue method for the

determination of 107 pesticides in cabbage and radish using QuEChERS sample

preparation method and gas chromatography mass spectrometry. Food Chemistry.

110(1): 207–213.

208 Lakshani et al.

World Health Organization. 2002. Recommended classification of pesticides by hazard and

guidelines to classification. World Health Organization, Geneva.

Latif Y. and S. T. H. Sherazi. 2011. Monitoring of pesticide residues in commonly used fruits

in Hyderabad Region, Pakistan. American Journal of Analytical Chemistry. 2 :46-52

pesticide residues in selected vegetables in several

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